Imaging assembly for intravascular imaging device and associated devices, systems, and methods

ABSTRACT

An intravascular imaging device is provided. In one embodiment, the intravascular imaging device includes a flexible elongate member sized and shaped for insertion into a vessel of a patient, the flexible elongate member having a proximal portion and a distal portion; a conductor extending between the proximal and distal portions of the flexible elongate member; an imaging assembly disposed at the distal portion of the flexible elongate member, the imaging assembly including: a flex circuit including a body and a tab extending therefrom, the tab having a conductive portion coupled to the conductor; and a support member around which the flex circuit is disposed, the support member including a shelf on which tab is positioned.

TECHNICAL FIELD

The present disclosure relates generally to intravascular ultrasound(IVUS) imaging and, in particular, to the distal structure of anintravascular imaging device. For example, the distal structure caninclude a support structure and a flex circuit that are arranged tofacilitate efficient assembly and operation of the intravascular imagingdevice.

BACKGROUND

Intravascular ultrasound (IVUS) imaging is widely used in interventionalcardiology as a diagnostic tool for assessing a diseased vessel, such asan artery, within the human body to determine the need for treatment, toguide the intervention, and/or to assess its effectiveness. An IVUSdevice including one or more ultrasound transducers is passed into thevessel and guided to the area to be imaged. The transducers emitultrasonic energy in order to create an image of the vessel of interest.Ultrasonic waves are partially reflected by discontinuities arising fromtissue structures (such as the various layers of the vessel wall), redblood cells, and other features of interest. Echoes from the reflectedwaves are received by the transducer and passed along to an IVUS imagingsystem. The imaging system processes the received ultrasound echoes toproduce a cross-sectional image of the vessel where the device isplaced.

Solid-state (also known as synthetic-aperture) IVUS catheters are one ofthe two types of IVUS devices commonly used today, the other type beingthe rotational IVUS catheter. Solid-state IVUS catheters carry a scannerassembly that includes an array of ultrasound transducers distributedaround its circumference along with one or more integrated circuitcontroller chips mounted adjacent to the transducer array. Thecontrollers select individual transducer elements (or groups ofelements) for transmitting an ultrasound pulse and for receiving theultrasound echo signal. By stepping through a sequence oftransmit-receive pairs, the solid-state IVUS system can synthesize theeffect of a mechanically scanned ultrasound transducer but withoutmoving parts (hence the solid-state designation). Since there is norotating mechanical element, the transducer array can be placed indirect contact with the blood and vessel tissue with minimal risk ofvessel trauma. Furthermore, because there is no rotating element, theelectrical interface is simplified. The solid-state scanner can be wireddirectly to the imaging system with a simple electrical cable and astandard detachable electrical connector, rather than the complexrotating electrical interface required for a rotational IVUS device.

Manufacturing an intravascular imaging device that can efficientlytraverse physiology within the human body is challenging. In thatregard, components at the distal portion of the imaging device causes anarea of high rigidity in the intravascular device, which increase thelikelihood of kinking as the intravascular is steered throughvasculature. When assembled, the distal components also have a largeouter diameter, which makes navigation of small diameter blood vesselschallenging.

Thus, there remains a need for intravascular ultrasound imaging systemthat overcomes the limitations of a rigid imaging assembly having alarge diameter while achieving efficient assembly and operation.

SUMMARY

Embodiments of the present disclosure provide an improved intravascularultrasound imaging system for generating images of a blood vessel. Adistal portion of an intravascular imaging device can include a flexcircuit and a support member around which the flex circuit ispositioned. Electronic controllers and transducers, which are used togenerate images of the vessel, are formed within the flex circuit.During assembly, the flex circuit can be rolled around the supportmember into a cylindrical shape. A proximal portion of the supportmember can include a shelf or a section of the support member bodyhaving a reduced diameter. A portion of the flex circuit at whichelectrical wires are soldered can rest on the shelf. The support membercan also include a hole that defines a throughway that allows theelectrical wires to extend between the flex circuit on an exterior ofthe intravascular device and an interior of the intravascular device.The shelf and throughway advantageously minimize the outer diameter ofthe intravascular device. A distal portion of the support member can besized and shaped to increase the surface area of adhesive contact with adistal component, which allows for efficient assembly of theintravascular imaging device. A portion of the flex circuit can bewrapped in a spiral or helical configuration around the support member,which can contribute to increased flexibility of the imaging assembly.

In one embodiment, an intravascular imaging device is provided. Theintravascular imaging device includes a flexible elongate member sizedand shaped for insertion into a vessel of a patient, the flexibleelongate member having a proximal portion and a distal portion; aconductor extending between the proximal and distal portions of theflexible elongate member; an imaging assembly disposed at the distalportion of the flexible elongate member, the imaging assembly including:a flex circuit including a body and a tab extending therefrom, the tabhaving a conductive portion coupled to the conductor; and a supportmember around which the flex circuit is disposed, the support memberincluding a shelf on which tab is positioned.

In some embodiments, the shelf is sized and shaped to accommodate thetab. In some embodiments, the shelf comprises a portion of the supportmember having a reduced diameter. In some embodiments, the supportmember is substantially cylindrical and the shelf is planar. In someembodiments, the tab is disposed at a distal portion of the flex circuitand the shelf is positioned at a distal portion of the support member.In some embodiments, the support member defines a lumen, and wherein thesupport member includes a recess adjacent to the shelf, the recessdefining throughway between the lumen and the tab through which theconductor extends.

In one embodiment, an intravascular imaging device is provided. Theintravascular imaging device includes s flexible elongate member sizedand shaped for insertion into a vessel of a patient, the flexibleelongate member having a proximal portion and a distal portion; aconductor extending between the proximal and distal portions of theflexible elongate member; an imaging assembly disposed at the distalportion of the flexible elongate member, the imaging assembly including:a flex circuit coupled to the conductor; and a support member aroundwhich the flex circuit is disposed, the support member including: alumen; and a recess defining throughway to the lumen through which theconductor extends.

In some embodiments, the recess is disposed at proximal portion of thesupport member. In some embodiments, the recess is shaped and shaped toaccommodate the conductor. In some embodiments, the recess extendsradially inward from an outer surface of the support member and throughan inner surface of the lumen. In some embodiments, the flex circuitincludes a body and a tab extending therefrom, the conductor beingcoupled to the flex circuit at a conductive portion of the tab; thesupport member includes shelf on which tab is positioned; and the recessis positioned adjacent to the shelf.

In one embodiment, an intravascular imaging device is provided. Theintravascular imaging device includes a flexible elongate member sizedand shaped for insertion into a vessel of a patient, the flexibleelongate member having a proximal portion and a distal portion; animaging assembly disposed at the distal portion of the flexible elongatemember, the imaging assembly including: a flex circuit; and a supportmember around which the flex circuit is disposed, the support memberhaving a flange at a distal portion thereof; a distal member extendingfrom the support member and disposed around the flange, wherein theflange is sized and shaped to facilitate coupling between the distalmember and the support member.

In some embodiments, the device further includes an adhesive disposedbetween the distal member and the support member, wherein the flange issized and shaped to increase a coverage area of the adhesive between thedistal member and the support member. In some embodiments, the flange istapered. In some embodiments, the flange comprises a screw-threadpattern. In some embodiments, the screw thread pattern comprises abuttress thread pattern. In some embodiments, the flange is sized andshaped to facilitate locking engagement between the distal member andthe support member.

In one embodiment, an intravascular imaging device is provided. Theintravascular imaging device includes a flexible elongate member sizedand shaped for insertion into a vessel of a patient, the flexibleelongate member having a proximal portion and a distal portion; animaging assembly disposed at the distal portion of the flexible elongatemember, the imaging assembly including: a flex circuit; and a supportmember around which the flex circuit is disposed; wherein a portion ofthe flex circuit is wrapped in a spiral configuration around the supportmember.

In some embodiments, the flex circuit includes a first section having aplurality of transducers, a second section having a plurality ofcontrollers, and a third section having a plurality of conductive tracesfacilitating communication between the plurality of the transducers andthe plurality of controllers. In some embodiments, the third section iswrapped in a spiral configuration around the support member. In someembodiments, a value of a dimension of the flex circuit in the thirdsection is less a value of the dimension of the flex circuit in thefirst and second sections. In some embodiments, a coating disposed overflex circuit, the coating configured to extend between gaps in theportion of the flex circuit is wrapped in a spiral configuration aroundthe support member.

In one embodiment, a method of assembling an intravascular imagingdevice is provided. The method includes obtaining a flex circuit havinga plurality of transducers, a plurality of controllers, and a pluralityof conductive traces facilitating communication between the plurality ofthe transducers and the plurality of controllers; positioning the flexcircuit around a support member, wherein the positioning includeswrapping a portion of the flex circuit around the support member in aspiral configuration; and coupling a flexible elongate member to atleast one of the flex circuit or the support member such that the flexcircuit and the support member are disposed at a distal portion of theflexible elongate member.

In some embodiments, the flex circuit includes a first section havingthe plurality of transducers, a second section having the plurality ofcontrollers, and a third section having the plurality of conductivetraces; and the third section is wrapped in the spiral configurationaround the support member. In some embodiments, the method furtherincludes applying a coating extending between gaps in the at least aportion of the flex circuit wrapped in a spiral configuration around thesupport member.

Additional aspects, features, and advantages of the present disclosurewill become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present disclosure will be describedwith reference to the accompanying drawings, of which:

FIG. 1 is a diagrammatic schematic view of an imaging system, accordingto aspects of the present disclosure.

FIG. 2 is a diagrammatic top view of a scanner assembly in a flatconfiguration, according to aspects of the present disclosure.

FIG. 3 is a diagrammatic side view of a scanner assembly in a rolledconfiguration around a support member, according to aspects of thepresent disclosure.

FIG. 4 is a diagrammatic cross-sectional side view of a distal portionof an intravascular device, according to aspects of the presentdisclosure.

FIG. 5 is a diagrammatic side view of a support member, according toaspects of the present disclosure.

FIG. 6 is a diagrammatic side view of an imaging assembly, including aflex circuit in a rolled configuration around a support member,according to aspects of the present disclosure.

FIG. 7A is a diagrammatic cross-sectional front view of the imagingassembly of FIG. 6 along section line 7A-7A of FIG. 6, according toaspects of the present disclosure.

FIG. 7B is a diagrammatic cross-sectional front view of the imagingassembly of FIG. 6 along section line 7B-7B of FIG. 6, according toaspects of the present disclosure.

FIG. 7C is a diagrammatic cross-sectional front view of the imagingassembly of FIG. 6 along section line 7C-7C of FIG. 6, according toaspects of the present disclosure.

FIG. 8A is a diagrammatic cross-sectional side view of a distal portionof an intravascular device, including a distal portion of a supportmember, according to aspects of the present disclosure.

FIG. 8B is a diagrammatic perspective view of a distal portion of asupport member, according to aspects of the present disclosure.

FIG. 9 is a diagrammatic cross-sectional side view of a distal portionof a support member, according to aspects of the present disclosure.

FIG. 10 is a diagrammatic cross-sectional side view of a distal portionof a support member, according to aspects of the present disclosure.

FIG. 11 is a diagrammatic cross-sectional side view of a distal portionof a support member, according to aspects of the present disclosure.

FIG. 12 is a diagrammatic cross-sectional side view of a distal portionof a support member, according to aspects of the present disclosure.

FIG. 13 is a diagrammatic top view of a distal portion of anintravascular device, including a distal portion of a support member,according to aspects of the present disclosure.

FIG. 14 is a diagrammatic top view of a scanner assembly in a flatconfiguration, according to aspects of the present disclosure.

FIG. 15 is a diagrammatic side view of a scanner assembly in a rolledconfiguration around a support member, according to aspects of thepresent disclosure.

FIG. 16 is a diagrammatic top view of a scanner assembly in a flatconfiguration, according to aspects of the present disclosure.

FIG. 17 is a diagrammatic top view of a scanner assembly in a flatconfiguration, according to aspects of the present disclosure.

FIG. 18 is a diagrammatic side view of a scanner assembly in a rolledconfiguration around a support member, according to aspects of thepresent disclosure.

FIG. 19 is a diagrammatic side view of a scanner assembly in a rolledconfiguration around a support member, according to aspects of thepresent disclosure.

FIG. 20 is a flow diagram of a method of assembling an intravasculardevice, according to aspects of the present disclosure.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It is nevertheless understood that no limitation tothe scope of the disclosure is intended. Any alterations and furthermodifications to the described devices, systems, and methods, and anyfurther application of the principles of the present disclosure arefully contemplated and included within the present disclosure as wouldnormally occur to one skilled in the art to which the disclosurerelates. For example, while the focusing system is described in terms ofcardiovascular imaging, it is understood that it is not intended to belimited to this application. The system is equally well suited to anyapplication requiring imaging within a confined cavity. In particular,it is fully contemplated that the features, components, and/or stepsdescribed with respect to one embodiment may be combined with thefeatures, components, and/or steps described with respect to otherembodiments of the present disclosure. For the sake of brevity, however,the numerous iterations of these combinations will not be describedseparately.

FIG. 1 is a diagrammatic schematic view of an intravascular ultrasound(IVUS) imaging system 100, according to aspects of the presentdisclosure. The IVUS imaging system 100 may include a solid-state IVUSdevice 102 such as a catheter, guide wire, or guide catheter, a patientinterface module (PIM) 104, an IVUS processing system or console 106,and a monitor 108.

At a high level, the IVUS device 102 emits ultrasonic energy from atransducer array 124 included in scanner assembly 110 mounted near adistal end of the catheter device. The ultrasonic energy is reflected bytissue structures in the medium, such as a vessel 120, surrounding thescanner assembly 110, and the ultrasound echo signals are received bythe transducer array 124. The PIM 104 transfers the received echosignals to the console or computer 106 where the ultrasound image(including the flow information) is reconstructed and displayed on themonitor 108. The console or computer 106 can include a processor and amemory. The computer or computing device 106 can be operable tofacilitate the features of the IVUS imaging system 100 described herein.For example, the processor can execute computer readable instructionsstored on the non-transitory tangible computer readable medium.

The PIM 104 facilitates communication of signals between the IVUSconsole 106 and the scanner assembly 110 included in the IVUS device102. This communication includes the steps of: (1) providing commands tointegrated circuit controller chip(s) 206A, 206B, illustrated in FIG. 2,included in the scanner assembly 110 to select the particular transducerarray element(s) to be used for transmit and receive, (2) providing thetransmit trigger signals to the integrated circuit controller chip(s)206A, 206B included in the scanner assembly 110 to activate thetransmitter circuitry to generate an electrical pulse to excite theselected transducer array element(s), and/or (3) accepting amplifiedecho signals received from the selected transducer array element(s) viaamplifiers included on the integrated circuit controller chip(s) 126 ofthe scanner assembly 110. In some embodiments, the PIM 104 performspreliminary processing of the echo data prior to relaying the data tothe console 106. In examples of such embodiments, the PIM 104 performsamplification, filtering, and/or aggregating of the data. In anembodiment, the PIM 104 also supplies high- and low-voltage DC power tosupport operation of the device 102 including circuitry within thescanner assembly 110.

The IVUS console 106 receives the echo data from the scanner assembly110 by way of the PIM 104 and processes the data to reconstruct an imageof the tissue structures in the medium surrounding the scanner assembly110. The console 106 outputs image data such that an image of the vessel120, such as a cross-sectional image of the vessel 120, is displayed onthe monitor 108. Vessel 120 may represent fluid filled or surroundedstructures, both natural and man-made. The vessel 120 may be within abody of a patient. The vessel 120 may be a blood vessel, as an artery ora vein of a patient's vascular system, including cardiac vasculature,peripheral vasculature, neural vasculature, renal vasculature, and/or orany other suitable lumen inside the body. For example, the device 102may be used to examine any number of anatomical locations and tissuetypes, including without limitation, organs including the liver, heart,kidneys, gall bladder, pancreas, lungs; ducts; intestines; nervoussystem structures including the brain, dural sac, spinal cord andperipheral nerves; the urinary tract; as well as valves within theblood, chambers or other parts of the heart, and/or other systems of thebody. In addition to natural structures, the device 102 may be may beused to examine man-made structures such as, but without limitation,heart valves, stents, shunts, filters and other devices.

In some embodiments, the IVUS device includes some features similar totraditional solid-state IVUS catheters, such as the EagleEye® catheteravailable from Volcano Corporation and those disclosed in U.S. Pat. No.7,846,101 hereby incorporated by reference in its entirety. For example,the IVUS device 102 includes the scanner assembly 110 near a distal endof the device 102 and a transmission line bundle 112 extending along thelongitudinal body of the device 102. The transmission line bundle orcable 112 can include a plurality of conductors, including one, two,three, four, five, six, seven, or more conductors 218 (FIG. 2). It isunderstood that any suitable gauge wire can be used for the conductors218. In an embodiment, the cable 112 can include a four-conductortransmission line arrangement with, e.g., 41 AWG gauge wires. In anembodiment, the cable 112 can include a seven-conductor transmissionline arrangement utilizing, e.g., 44 AWG gauge wires. In someembodiments, 43 AWG gauge wires can be used.

The transmission line bundle 112 terminates in a PIM connector 114 at aproximal end of the device 102. The PIM connector 114 electricallycouples the transmission line bundle 112 to the PIM 104 and physicallycouples the IVUS device 102 to the PIM 104. In an embodiment, the IVUSdevice 102 further includes a guide wire exit port 116. Accordingly, insome instances the IVUS device is a rapid-exchange catheter. The guidewire exit port 116 allows a guide wire 118 to be inserted towards thedistal end in order to direct the device 102 through the vessel 120.

FIG. 2 is a top view of a portion of an ultrasound scanner assembly 110according to an embodiment of the present disclosure. The assembly 110includes a transducer array 124 formed in a transducer region 204 andtransducer control logic dies 206 (including dies 206A and 206B) formedin a control region 208, with a transition region 210 disposedtherebetween. The transducer control logic dies 206 and the transducers212 are mounted on a flex circuit 214 that is shown in a flatconfiguration in FIG. 2. FIG. 3 illustrates a rolled configuration ofthe flex circuit 214. The transducer array 202 is a non-limiting exampleof a medical sensor element and/or a medical sensor element array. Thetransducer control logic dies 206 is a non-limiting example of a controlcircuit. The transducer region 204 is disposed adjacent a distal portion220 of the flex circuit 214. The control region 208 is disposed adjacentthe proximal portion 222 of the flex circuit 214. The transition region210 is disposed between the control region 208 and the transducer region204. Dimensions of the transducer region 204, the control region 208,and the transition region 210 (e.g., lengths 225, 227, 229) can vary indifferent embodiments. In some embodiments, the lengths 225, 227, 229can be substantially similar or a length 227 of the transition region210 can be greater than lengths 225, 229 of the transducer region andcontroller region, respectively. While the imaging assembly 110 isdescribed as including a flex circuit, it is understood that thetransducers and/or controllers may be arranged to form the imagingassembly 110 in other configurations, including those omitting a flexcircuit.

The transducer array 124 may include any number and type of ultrasoundtransducers 212, although for clarity only a limited number ofultrasound transducers are illustrated in FIG. 2. In an embodiment, thetransducer array 124 includes 64 individual ultrasound transducers 212.In a further embodiment, the transducer array 124 includes 32 ultrasoundtransducers 212. Other numbers are both contemplated and provided for.With respect to the types of transducers, in an embodiment, theultrasound transducers 124 are piezoelectric micromachined ultrasoundtransducers (PMUTs) fabricated on a microelectromechanical system (MEMS)substrate using a polymer piezoelectric material, for example asdisclosed in U.S. Pat. No. 6,641,540, which is hereby incorporated byreference in its entirety. In alternate embodiments, the transducerarray includes piezoelectric zirconate transducers (PZT) transducerssuch as bulk PZT transducers, capacitive micromachined ultrasoundtransducers (cMUTs), single crystal piezoelectric materials, othersuitable ultrasound transmitters and receivers, and/or combinationsthereof.

The scanner assembly 110 may include various transducer control logic,which in the illustrated embodiment is divided into discrete controllogic dies 206. In various examples, the control logic of the scannerassembly 110 performs: decoding control signals sent by the PIM 104across the cable 112, driving one or more transducers 212 to emit anultrasonic signal, selecting one or more transducers 212 to receive areflected echo of the ultrasonic signal, amplifying a signalrepresenting the received echo, and/or transmitting the signal to thePIM across the cable 112. In the illustrated embodiment, a scannerassembly 110 having 64 ultrasound transducers 212 divides the controllogic across nine control logic dies 206, of which five are shown inFIG. 2. Designs incorporating other numbers of control logic dies 206including 8, 9, 16, 17 and more are utilized in other embodiments. Ingeneral, the control logic dies 206 are characterized by the number oftransducers they are capable of driving, and exemplary control logicdies 206 drive 4, 8, and/or 16 transducers.

The control logic dies are not necessarily homogenous. In someembodiments, a single controller is designated a master control logicdie 206A and contains the communication interface for the cable 112.Accordingly, the master control circuit may include control logic thatdecodes control signals received over the cable 112, transmits controlresponses over the cable 112, amplifies echo signals, and/or transmitsthe echo signals over the cable 112. The remaining controllers are slavecontrollers 206B. The slave controllers 206B may include control logicthat drives a transducer 212 to emit an ultrasonic signal and selects atransducer 212 to receive an echo. In the depicted embodiment, themaster controller 206A does not directly control any transducers 212. Inother embodiments, the master controller 206A drives the same number oftransducers 212 as the slave controllers 206B or drives a reduced set oftransducers 212 as compared to the slave controllers 206B. In anexemplary embodiment, a single master controller 206A and eight slavecontrollers 206B are provided with eight transducers assigned to eachslave controller 206B.

The flex circuit 214, on which the transducer control logic dies 206 andthe transducers 212 are mounted, provides structural support andinterconnects for electrical coupling. The flex circuit 214 may beconstructed to include a film layer of a flexible polyimide materialsuch as KAPTON™ (trademark of DuPont). Other suitable materials includepolyester films, polyimide films, polyethylene napthalate films, orpolyetherimide films, other flexible printed semiconductor substrates aswell as products such as Upilex® (registered trademark of UbeIndustries) and TEFLON® (registered trademark of E.I. du Pont). In theflat configuration illustrated in FIG. 2, the flex circuit 214 has agenerally rectangular shape. As shown and described herein, the flexcircuit 214 is configured to be wrapped around a support member 230(FIG. 3) to form a cylindrical toroid in some instances. Therefore, thethickness of the film layer of the flex circuit 214 is generally relatedto the degree of curvature in the final assembled scanner assembly 110.In some embodiments, the film layer is between 5 μm and 100 μm, withsome particular embodiments being between 12.7 μm and 25.1 μm.

To electrically interconnect the control logic dies 206 and thetransducers 212, in an embodiment, the flex circuit 214 further includesconductive traces 216 formed on the film layer that carry signalsbetween the control logic dies 206 and the transducers 212. Inparticular, the conductive traces 216 providing communication betweenthe control logic dies 206 and the transducers 212 extend along the flexcircuit 214 within the transition region 210. In some instances, theconductive traces 216 can also facilitate electrical communicationbetween the master controller 206A and the slave controllers 206B. Theconductive traces 216 can also provide a set of conductive pads thatcontact the conductors 218 of cable 112 when the conductors 218 of thecable 112 are mechanically and electrically coupled to the flex circuit214. Suitable materials for the conductive traces 216 include copper,gold, aluminum, silver, tantalum, nickel, and tin, and may be depositedon the flex circuit 214 by processes such as sputtering, plating, andetching. In an embodiment, the flex circuit 214 includes a chromiumadhesion layer. The width and thickness of the conductive traces 216 areselected to provide proper conductivity and resilience when the flexcircuit 214 is rolled. In that regard, an exemplary range for thethickness of a conductive trace 216 and/or conductive pad is between10-50 μm. For example, in an embodiment, 20 μm conductive traces 216 areseparated by 20 μm of space. The width of a conductive trace 216 on theflex circuit 214 may be further determined by the width of the conductor218 to be coupled to the trace/pad.

The flex circuit 214 can include a conductor interface 220 in someembodiments. The conductor interface 220 can be a location of the flexcircuit 214 where the conductors 218 of the cable 114 are coupled to theflex circuit 214. For example, the bare conductors of the cable 114 areelectrically coupled to the flex circuit 214 at the conductor interface220. The conductor interface 220 can be tab extending from the main bodyof flex circuit 214. In that regard, the main body of the flex circuit214 can refer collectively to the transducer region 204, controllerregion 208, and the transition region 210. In the illustratedembodiment, the conductor interface 220 extends from the proximalportion 222 of the flex circuit 214. In other embodiments, the conductorinterface 220 is positioned at other parts of the flex circuit 214, suchas the distal portion 220, or the flex circuit 214 omits the conductorinterface 220. A value of a dimension of the tab or conductor interface220, such as a width 224, can be less than the value of a dimension ofthe main body of the flex circuit 214, such as a width 226. In someembodiments, the substrate forming the conductor interface 220 is madeof the same material(s) and/or is similarly flexible as the flex circuit214. In other embodiments, the conductor interface 220 is made ofdifferent materials and/or is comparatively more rigid than the flexcircuit 214. For example, the conductor interface 220 can be made of aplastic, thermoplastic, polymer, hard polymer, etc., includingpolyoxymethylene (e.g., DELRIN®), polyether ether ketone (PEEK), nylon,and/or other suitable materials. As described in greater detail herein,the support member 230, the flex circuit 214, the conductor interface220 and/or the conductor(s) 218 can be variously configured tofacilitate efficient manufacturing and operation of the scanner assembly110.

In some instances, the scanner assembly 110 is transitioned from a flatconfiguration (FIG. 2) to a rolled or more cylindrical configuration(FIGS. 3 and 4). For example, in some embodiments, techniques areutilized as disclosed in one or more of U.S. Pat. No. 6,776,763, titled“ULTRASONIC TRANSDUCER ARRAY AND METHOD OF MANUFACTURING THE SAME” andU.S. Pat. No. 7,226,417, titled “HIGH RESOLUTION INTRAVASCULARULTRASOUND TRANSDUCER ASSEMBLY HAVING A FLEXIBLE SUBSTRATE,” each ofwhich is hereby incorporated by reference in its entirety.

As shown in FIGS. 3 and 4, the flex circuit 214 is positioned around thesupport member 230 in the rolled configuration. FIG. 3 is a diagrammaticside view with the flex circuit 214 in the rolled configuration aroundthe support member 230, according to aspects of the present disclosure.FIG. 4 is a diagrammatic cross-sectional side view of a distal portionof the intravascular device 110, including the flex circuit 214 and thesupport member 230, according to aspects of the present disclosure.

The support member 230 can be referenced as a unibody in some instances.The support member 230 can be composed of a metallic material, such asstainless steel, or non-metallic material, such as a plastic or polymeras described in U.S. Provisional Application No. 61/985,220, “Pre-DopedSolid Substrate for Intravascular Devices,” filed Apr. 28, 2014, theentirety of which is hereby incorporated by reference herein. Thesupport member 230 can be ferrule having a distal portion 262 and aproximal portion 264. The support member 230 can define a lumen 236extending longitudinally therethrough. The lumen 236 is in communicationwith the exit port 116 and is sized and shaped to receive the guide wire118 (FIG. 1). The support member 230 can be manufactured accordingly toany suitable process. For example, the support member 230 can bemachined, such as by removing material from a blank to shape the supportmember 230, or molded, such as by an injection molding process. In someembodiments, the support member 230 may be integrally formed as aunitary structure, while in other embodiments the support member 230 maybe formed of different components, such as a ferrule and stands 242,244, that are fixedly coupled to one another.

Stands 242, 244 that extend vertically are provided at the distal andproximal portions 262, 264, respectively, of the support member 230. Thestands 242, 244 elevate and support the distal and proximal portions ofthe flex circuit 214. In that regard, portions of the flex circuit 214,such as the transducer portion 204, can be spaced from a central bodyportion of the support member 230 extending between the stands 242, 244.The stands 242, 244 can have the same outer diameter or different outerdiameters. For example, the distal stand 242 can have a larger orsmaller outer diameter than the proximal stand 244. To improve acousticperformance, any cavities between the flex circuit 214 and the surfaceof the support member 230 are filled with a backing material 246. Theliquid backing material 246 can be introduced between the flex circuit214 and the support member 230 via passageways 235 in the stands 242,244. In some embodiments, suction can be applied via the passageways 235of one of the stands 242, 244, while the liquid backing material 246 isfed between the flex circuit 214 and the support member 230 via thepassageways 235 of the other of the stands 242, 244. The backingmaterial can be cured to allow it to solidify and set. In variousembodiments, the support member 230 includes more than two stands 242,244, only one of the stands 242, 244, or neither of the stands. In thatregard the support member 230 can have an increased diameter distalportion 262 and/or increased diameter proximal portion 264 that is sizedand shaped to elevate and support the distal and/or proximal portions ofthe flex circuit 214.

The support member 230 can be substantially cylindrical in someembodiments. Other shapes of the support member 230 are alsocontemplated including geometrical, non-geometrical, symmetrical,non-symmetrical, cross-sectional profiles. Different portions thesupport member 230 can be variously shaped in other embodiments. Forexample, the proximal portion 264 can have a larger outer diameter thanthe outer diameters of the distal portion 262 or a central portionextending between the distal and proximal portions 262, 264. In someembodiments, an inner diameter of the support member 230 (e.g., thediameter of the lumen 236) can correspondingly increase or decrease asthe outer diameter changes. In other embodiments, the inner diameter ofthe support member 230 remains the same despite variations in the outerdiameter.

A proximal inner member 256 and a proximal outer member 254 are coupledto the proximal portion 264 of the support member 230. The proximalinner member 256 and/or the proximal outer member 254 can be flexibleelongate member that extend from proximal portion of the intravascular102, such as the proximal connector 114, to the imaging assembly 110.For example, the proximal inner member 256 can be received within aproximal flange 234. The proximal outer member 254 abuts and is incontact with the flex circuit 214. A distal member 252 is coupled to thedistal portion 262 of the support member 230. The distal member 252 canbe a flexible component that defines a distal most portion of theintravascular device 102. For example, the distal member 252 ispositioned around the distal flange 232. The distal member 252 can abutand be in contact with the flex circuit 214 and the stand 242. Thedistal member 252 can be the distal-most component of the intravasculardevice 102.

One or more adhesives can be disposed between various components at thedistal portion of the intravascular device 102. For example, one or moreof the flex circuit 214, the support member 230, the distal member 252,the proximal inner member 256, and/or the proximal outer member 254 canbe coupled to one another via an adhesive.

FIGS. 5, 6, 7A, 7B, and 7C illustrate an exemplary embodiment of asupport member 330. FIG. 5 is a diagrammatic side view of the supportmember 330. FIG. 6 is a diagrammatic side view of an imaging assembly300, including the flex circuit 214 in a rolled configuration around thesupport member 330. FIGS. 7A, 7B, and 7C are diagrammaticcross-sectional front views of imaging assembly 300 of FIG. 6 alongsection lines 7A-7A, 7B-7B, and 7C-C of FIG. 6, according to aspects ofthe present disclosure.

The support member 330 can be similar to the support member 230 in someaspects. The support member 330 includes a distal portion 262 and aproximal portion 364. A distal flange 332 and a stand 342 havingpassageways 335 are provided at the distal portion 262. The proximalportion 364 of the support member 330 is sized and shaped to accommodatecomponents of the imaging assembly 300, including the conductors 218 andthe conductor interface 220 flex circuit 214, and to allow efficientassembly the intravascular device.

A shelf 302 is provided on a proximal flange 334 of the support member330. The shelf 302 is sized and shaped to accommodate the conductorinterface 220. As shown in FIGS. 6 and 7A, when the flex circuit 214 isin a rolled configuration around the support member 330, the conductorinterface 220 is received and rests on the shelf 302. The shelf 302 isan area of the proximal flange 334 having a reduced outer diameterrelative to other parts of the proximal flange 334. The reduced outerdiameter of the shelf 302 advantageously accommodates the thickness ofconductor interface 220 and/or the conductors 218 so that the outerdiameter of the imaging assembly 300 does not increase in the area ofthe conductor interface 220 when the flex circuit 214 is wrapped aroundsupport member 330. This advantageously prevents a bulge in the outerdiameter of the imaging assembly 300 in the area of the conductorinterface. The shelf can have a substantially planar surface that abutsor is in contact with an inferior side of the conductor interface 220.The conductor interface 220 can be affixed to the shelf 302 via anadhesive. In some embodiments, at least a portion of the shelf 302 iscurved, such as in a concave manner, to provide space for the adhesive.

As shown in FIGS. 6 and 7B, the support member 330 can include athroughway 304. The throughway 304 can be a recess formed the supportmember 330 that defines a lumen. The conductors 218 extend from theconductor interface 220 into a lumen 336 of the support member 330 viathe throughway or recess 304. The throughway 304 can be disposed at theproximal portion 364 of the support member 330. For example, thethroughway 304 can be positioned adjacent to the shelf 302 such that thethroughway 304 is proximate to the conductor interface 220 when the flexcircuit 214 is wrapped around the support member 330. The recess 304 canbe sized and shaped to accommodate the one, two, three, four or moreconductors 218. For example, the diameter of the recess 304 can beselected to allow the one or more conductors 218 to pass between theoutside of the support member 330 and the lumen 336. The recess 304 canextend radially inward from an outer surface 314 of the support member330 and through an inner surface 312 of the lumen 336. FIG. 7Cillustrates the one or more conductors 336 extending within the lumen336. The throughway 304 advantageously minimizes the assembled, outerdiameter of the imaging assembly 300 by guiding the conductors into thelumen 336 rather than the conductors 218 extending along the outersurface 314 of the support member 330. An intravascular device with thesmaller diameter imaging assembly 300 can traverse physiology within thehuman body, such as a blood vessel, more efficiently than anintravascular device or imaging assembly with a larger diameter.

FIGS. 8A, 8B, 9, 10, 11, and 12 illustrate exemplary embodiments of adistal flange 432 of a support member 430. FIG. 8A is a diagrammaticcross-sectional side view of a distal portion of an intravascular device103, including a distal portion 462 of a support member 430. FIG. 8B isa diagrammatic perspective view of the distal portion 462 of the supportmember 430. FIGS. 9, 10, 11, and 12 are diagrammatic cross-sectionalside views of the distal portion 462 of the support member 430.

The support member 430 can be similar in some aspects to the supportmembers 230 and 330. The support member 430 includes a stand 442 havingan increased outer diameter relative to a central portion of the supportmember 430 (e.g., a portion of the support member 430 between proximaland distal stands, or between the stand 442 and an increased diameterproximal portion of the support member 430). The stand 442 is configuredmaintain a space between the flex circuit 214 and the central portion ofthe support member 430 to facilitate operation of the transducers of theflex circuit 214. The support member 430 defines a lumen 436 sized andshaped to receive a guide wire.

To assemble the intravascular device 103, adhesive 470 can be positionedon the distal flange 432 and then the distal member 452 is positionedaround the distal flange 432 to the couple to the distal member 452 andthe support member 430. The shape of the distal flange 432 can determinethe surface area of contact between the distal member 452 and the distalflange 432. An increased surface area of contact allows for additionaladhesive to bind the distal member 452 and the distal flange 432together. Various shapes of the distal flange 432, such as thoseillustrated in FIGS. 8A-12, can facilitate efficient coupling betweenthe distal member 452 and the distal flange 432. The shapes of thedistal flange 432 can be manufactured according to any suitable process.For example, the distal flange 432, as well as support member 430, canbe machined, laser cut, molded, and/or combinations thereof.

FIGS. 8A and 8 b show a distal flange 432 a having a screw threadpattern, such as a buttress thread pattern. FIG. 9 illustrates thedistal portion 462 of the support member 430 having a straight or linearcross-sectional profile such that a distal flange 432 b is substantiallycylindrical. A distal flange 432 c of FIG. 10 has a taperedcross-sectional profile. FIG. 11 shows the distal flange 432 d having astair step pattern. A distal flange 432 e of the FIG. 12 has a screwthread pattern. As similarly described above, the various shapes of thedistal flange 432 advantageously provide additional coverage area foradhesive to be positioned between the distal member 452 and the distalflange 432. One or more of the shapes of the distal flange 432, such asthe screw thread pattern of distal flange 432 e (FIG. 12) and/or thebuttress thread pattern of distal flange 432 a (FIGS. 8A and 8B) canalso provide locking engagement of the distal member 452 and the distalflange 432 a after the distal member 452 is slid over and around thedistal flange 432 a. In that regard, the crests of the distal flanges432 a, 432 e can engage the flexible body of the distal member 452 suchthat removal of the distal member 452 is inhibited after the distalmember 452 is slid over and around the distal flange 432 a. The roots ofthe distal flanges 432 a, 432 e can provide additional areas for theadhesive to reside and to facilitate adhesion of the distal member 452and the support member 430.

FIG. 13 is a diagrammatic top view of a distal portion of anintravascular device 105, including a distal portion 562 of a supportmember 530. Support member 530 can be similar to the support members230, 330, and 430 in some aspects. The intravascular device 105 includesan imaging assembly 500, such as the flex circuit 214. The flex circuit214 is shown in a flat configuration, aligned with the support member530, and prior to being wrapped around the support 530. Increaseddiameter portions 542, 544 support and elevate the flex circuit from acentral body portion of the support member 530 that extends between theincrease diameter portions 542, 544. While the illustrated embodimentshows that the increased diameter portion 544 has larger outer diameterthan the increased diameter portion 542, it is understood that theincreased diameter portions 542, 544 can have the same diameter, or theincreased diameter portion 542 can have a smaller outer diameter thanthe increased diameter portion 544. The guide wire 118 extends throughthe lumen of the support member 530.

A distal flange 532 of the support member 530 defines a distal most-end533 of the intravascular device 105. In that regard, the intravasculardevice 105 omits a distal member that would otherwise be the distal-mostcomponent of the intravascular device 105. By omitting a distinct distalmember, the total number of components can be minimized, allowing formore efficient assembly of the intravascular device 105. The distalflange 532 is can have any shape, including the tapered shape shown inthe illustrated embodiment. The flex circuit 214 can include a distalregion 215 that extends distally of the transducer region 204. Thedistal region 215 is wrapped around the distal flange 532 to assemblethe intravascular device 105. An adhesive can affix the inferior side ofthe distal region 215 to the outer surface of the distal flange 532.

FIGS. 14-17 illustrate exemplary embodiments of scanner assembly 600,including a flex circuit 614. A least a portion of the flex circuit 614is configured to be spirally or helically wrapped around a supportmember 630. The scanner assembly 600 can be positioned at a distalportion of an intravascular device 107. Having a portion of the flexcircuit 614 in a spiral or helical configuration can advantageouslyincrease the flexibility of the scanner assembly 600 and decrease thelikelihood of kinking while the intravascular device 107 is navigatedthrough a patient's vasculature. FIGS. 14, 16, and 17 are diagrammatictop views of a scanner assembly 600 in a flat configuration. FIG. 15 isa diagrammatic side view of the scanner assembly 600, including the flexcircuit 614, in a rolled configuration around the support member 630.

The scanner assembly 600 and the flex circuit 614 can be similar in somerespects to scanner assembly 110 and the flex circuit 214, respectively.The imaging assembly 600 includes a transducer region 604 having aplurality of transducers 212 at a distal portion 620 and a controllerregion 608 having plurality of controllers 206B at a proximal portion622. A transition region 610 having a plurality of conductive traces 216extending in a central portion between the distal and proximal portions620, 622 facilitates communication between the plurality of transducers212 and a plurality of controllers 206B. The transition region 610comprises a strip 684 on which the conductive traces 216 are formed. Onedimension of the strip 684, such as a width 682, can have a smallervalue than a corresponding dimension, such as a width 680, of thetransducer region 604 and/or the controller region 608. The width 682 ofthe transition region 610 and/or the strip 684 can be any suitablevalue, including between approximately 0.010″ and 0.415″. The width 680of the transducer region 604 and/or the controller region 608 can bebetween approximately 0.081″ and 0.415″, for example. The width 680and/or width 682 can be suitable for an intravascular device 102 havinga size between approximately 2 Fr and approximately 10 Fr, for example.Another dimension of the strip 684, such as a length 691, can have alarger value than a corresponding dimension, such as lengths 690, 692 ofthe transducer region 604 and the controller region 608, respectively.The length 691 of the transition region 610 and/or the strip 684 can beany suitable value, including between approximately 0.005″ and 5.000″.In that regard, the length 691 can be suitable for a relatively shortbendable transition region 610 and/or a relatively longer transitionregion that may be rolled approximately ten revolutions around anapproximately 10 Fr intravascular device 102, for example. The length690 of the transducer region 604 can be between approximately 0.025″ and0.250″, for example. The length 692 of the controller region 608 can bebetween approximately 0.025″ and 0.250″, for example.

In the illustrated embodiment of FIG. 15, the flex circuit 614 ispositioned around support member 630. Various regions of the flexcircuit 614 can be positioned around the support member 630 in differentconfigurations. For example, the transducer region 604 and thecontroller region 608 can have a cylindrical or cylindrical toroidconfiguration when rolled around the support member 630. The transitionregion 610 can have a spiral or helical configuration when positionedaround the support member 630. The strip 684 of the transition region610 is sized and shaped to be spirally wrapped around the support member630. The strip 684 can be spirally wrapped around the support member 614with any suitable number of windings, depending on the length 691. Forexample, the strip or spirally wrapped portion 684 can be wound aroundthe support member one, two, three, four, or more times. The strip 684can be wrapped with a right-handed or left-handed orientation indifferent embodiments (FIGS. 15 and 18).

The support member 630 can be variously sized and shaped to support theflexi circuit 614, including the strip or spirally wrapped portion 684.In FIG. 15, increased diameter portions 642, 644 support the flexcircuit such that the transducers 212 are spaced from the body portionof the support member 630 extending between the increase diameterportions 642, 644. In that regard, the spirally wrapped portion 684 isin contact with the support member 630 as the spirally wrapped portion684 is positioned around the increased diameter portion 684. In someembodiments, the spirally wrapped portion 684 is wrapped around aportion of the support member 630 having a relatively smaller diameter.In some embodiments, an acoustic backing material is disposed between ina space between the spirally wrapped portion 684 and the support member630. For example, during assembly, the strip 684 can be wrapped around amandrel that is later removed. The backing material can be introducedinto the space between the flex circuit 614 and the support member 630.

While FIG. 14 illustrates that the transition region 610 of the flexcircuit 614 includes one strip or spirally wrapped portion 684, it isunderstood that the transition region 610 can include any suitablenumber of strips, include one, two, three, four, or more strips. Forexample, FIG. 16 illustrates a configuration of the flex circuitincluding two strips 685, 686. The strips 685, 686 include conductivetraces that facilitate communication between the transducers 212 and thecontrollers 206B. The multiple strips are sized and shaped to behelically or spirally wrapped around the support member 630.

The strip 684 (FIG. 14) and strips 685, 686 (FIG. 16) are positioned atright angles relative to the transducer region 604 and the controllerregion 608. Other suitable orientations of the one or more strips arecontemplated. For example, as illustrated in FIG. 17, the strip 687extends at an oblique angle relative to the transducer region 604 andthe controller region 608. The strip 687 includes conductive traces thatfacilitate communication between the transducers 212 and the controllers206B. The strip 687 is sized and shaped to be helically or spirallywrapped around the support member 630.

Yet other orientations for the transition region 610 are contemplated.For example, the one or more strips configured to be helically orspirally wrapped can be parallel or non-parallel. For example, thestrips may intersect or overlap in some embodiments.

FIGS. 18 and 19 illustrate an exemplary embodiment the imaging assembly700, including a flex circuit 714. A least a portion of the flex circuit714 is configured to be spirally or helically wrapped around a supportmember 730. The scanner assembly 700 can be positioned at a distalportion of an intravascular device 109. FIGS. 18 and 19 are diagrammaticside views of the scanner assembly 700 in a rolled configuration. FIG.19 illustrates exemplary positions of the various electronic components(e.g., controllers, transducers, and/or conductive traces) on the flexcircuit 714, while FIG. 18 illustrates the flexible circuit 714 withoutthe electronic components for clarity.

The flex circuit 714 is positioned around the support member 730. Inthat regard, the distal and proximal portions 762, 764 of the flexcircuit 714 are supported by the stands 742, 744. The flex circuit 714is spaced from the central portion of the support member 730 between thestands 742, 744. The space between the flex circuit 714 and the supportmember 730 can be filled with a backing material. A portion of the flexcircuit 714, such as the strip 788 is spirally or helically wrappedaround the support member 730. In some embodiments, the strip 788 iswrapped directly around the central portion of the support member 730that has a smaller outer diameter than the stands 742, 744. In otherembodiments, the strip 788 is spirally or helically wrapped around amandrel surrounding the support member 730. An acoustic backing materialis introduced between the support member 730 and the flex circuit 714,and the mandrel is removed after the backing material has cured suchthat the strip 788 is spirally or helically wrapped around the backingmaterial.

A coating 789 has been applied to the imaging assembly 700. The coating789 can be a flexible outer layer that seals the flex circuit 714. Thecoating 789 extends over the outer surface of the flex circuit 714. Inparticular, the coating 789 extends between the one or more gaps 793between windings of the strip 788. In that regard, a dimension of thegaps 793, such as a width, can have any suitable value. For example,individual windings of the strip 788 can be closely-spaced such that thegaps 793 are relatively small or widely-spaced such that the gaps 793are relatively large. The width of the gaps 793 can be betweenapproximately 0.001″ and approximately 0.040″, in some embodiments. Thewidth of the each of the gaps 793 can be equal or individual windings ofthe strip 788 can be spaced by different widths. The flex circuit 714can have one or more gaps 793, depending on the number of windings ofthe strip 793 around the support member 730.

In the illustrated embodiment of FIG. 15, the spirally wrapped portion684 of the flex circuit extends between the transducer region 604 andthe controller region 608. In some embodiments, such as the embodimentof FIG. 19, the strip 788 can be helically or spirally wrapped aroundthe support member 730 within the controller region 608 and thetransition region 610. For example, the conductive traces formed withinthe spirally wrapped portion 788 can extend from a proximal portion ofthe one or more controllers within the controller region 608 to the oneor more transducers within the transducer region 604.

FIG. 20 is a flow diagram of a method 800 of assembling an intravascularimaging device, such as the intravascular devices 102, 105, 107, 109, asdescribed herein. It is understood that the steps of method 800 may beperformed in a different order than shown in FIG. 20, additional stepscan be provided before, during, and after the steps, and/or some of thesteps described can be replaced or eliminated in other embodiments. Thesteps of the method 800 can be carried out by a manufacturer of theintravascular imaging device.

At step 810, the method 800 includes obtaining a flex circuit. The flexcircuit forms a part of an imaging assembly of the intravascular device.In that regard, the flex circuit comprises a plurality of transducers, aplurality of controllers, and a plurality of conductive tracesfacilitating communication between the transducers and the controllers.For example, the flex circuit can include a first section having theplurality of transducers, a second section having a plurality ofcontrollers, and a third section having the plurality of conductivetraces. In some embodiments, the first and second sections can bepositioned at proximal and/or distal portions of the flex circuit. Thethird section having the conductive traces can extend in a centralportion of the flex circuit between the first and second sections.

At step 820, the method 800 includes positioning the flex circuit arounda support member. The support member can be a substantially cylindricalcomponent. The flex circuit can be obtained in step 810 in a flatconfiguration. Step 820 can include transitioning at least a portion ofthe flex circuit into a rolled configuration around the support member.For example, the step 820 can include positioning the first, section,and/or third sections of the flex circuit around the support member. Thestep 820 can also include aligning the flex circuit with the supportmember. For example, the support member can include one more increaseddiameter portions to support the proximal and distal portions of theflex circuit. The proximal and/or distal portions of the flex circuitcan be aligned with the support member prior to be rolled around thesupport member.

At step 830, the method 800 includes wrapping a portion of the flexcircuit around the support member in a spiral or helical configurationaround the support member. For example, the step 830 can includewrapping the third section having the plurality of conductive traces ina helical or spiral configuration around the support member.

In some embodiments, the steps 820 and 830 can include first rolling oneof the proximal or distal portions of the flex circuit (e.g., the firstor second section) into a cylindrical or cylindrical toroidconfiguration around the support member. Then, a central portion of theflex circuit (e.g., the third section) can be spirally or helicallywrapped around the support member. Next, the other of proximal or distalportions of the flex circuit (e.g., the first or second section) can berolled into a cylindrical or cylindrical toroid configuration around thesupport member.

In some embodiments, the method 800 includes disposing the conductivetraces facilitating electrical communication between the transducers andcontrollers onto a film layer of a flexible polyimide material, such asKAPTON™ (trademark of DuPont), forming the flex circuit. For example,the conductive traces can be wrapped in a spiral or helicalconfiguration onto the flexible substrate. The pre-assembled flexcircuit, including the transducers, controllers, and conductive traces,can then be wrapped/rolled around the support member to form the imagingassembly.

In some embodiments, the method 800 can include positioning a mandrelaround the support member and positioning the flex circuit around themandrel. The method 800 can also include introducing a liquid acousticbacking material between the flex circuit and the support member. Themethod 800 can also include removing the mandrel after the liquidacoustic backing material has cured.

At step 840, the method 800 can include applying a coating to the flexcircuit. The coating can extend between gaps in the flex circuit, suchas gaps in the windings in the portion of the flex circuit helically orspirally wound around the support member.

At step 850, the method 800 can include coupling the flex circuit and/orthe support member to one or more flex elongate member. For example, oneor more proximal flexible elongate members (e.g., an inner member and/oran outer member) are coupled to the flex circuit and/or the supportmember. In that regard, the flex circuit and/or the support member arepositioned at the distal portion of the flexible elongate member. Themethod 800 can also include coupling the flex circuit and/or the supportmember to a distal component that defines a distal-most end of theintravascular imaging device. The method 800 can include introducingadhesive to affix the flex circuit and the support member and/or othercomponents of the intravascular imaging device.

Various embodiments of an intravascular device and/or imaging assemblycan include features described in U.S. Provisional App. Ser. No. ______(Atty Dkt. No. IVI-0090-PRO/44755.1594PV01), filed on an even dateherewith, U.S. Provisional App. Ser. No. ______ (Atty Dkt. No.IVI-0091-PRO/44755.1595PV01), filed on an even date herewith, U.S.Provisional App. Ser. No. ______ (Atty Dkt. No.IVI-0092-PRO/44755.1596PV01), filed on an even date herewith, and U.S.Provisional App. Ser. No. ______ (Atty Dkt. No.IVI-0093-PRO/44755.1597PV01), filed on an even date herewith, theentireties of which are hereby incorporated by reference herein.

Persons skilled in the art will recognize that the apparatus, systems,and methods described above can be modified in various ways.Accordingly, persons of ordinary skill in the art will appreciate thatthe embodiments encompassed by the present disclosure are not limited tothe particular exemplary embodiments described above. In that regard,although illustrative embodiments have been shown and described, a widerange of modification, change, and substitution is contemplated in theforegoing disclosure. It is understood that such variations may be madeto the foregoing without departing from the scope of the presentdisclosure. Accordingly, it is appropriate that the appended claims beconstrued broadly and in a manner consistent with the presentdisclosure.

1. An intravascular imaging device comprising: a flexible elongatemember sized and shaped for insertion into a vessel of a patient, theflexible elongate member comprising a proximal portion and a distalportion; a conductor extending between the proximal and distal portionsof the flexible elongate member; an imaging assembly disposed at thedistal portion of the flexible elongate member, the imaging assemblyincluding: a flex circuit including a body and a tab extendingtherefrom, the tab comprising a conductive portion coupled to theconductor; and a support member around which the flex circuit isdisposed, the support member including a shelf on which tab ispositioned, the shelf comprising a reduced diameter portion of thesupport member.
 2. The intravascular imaging device of claim 1, whereinthe shelf is sized and shaped to accommodate the tab such than an outerdiameter of the imaging assembly does not increase in an area comprisingthe shelf and the tab.
 3. (canceled)
 4. The intravascular imaging deviceof claim 1, wherein the support member is substantially cylindrical andthe shelf is planar.
 5. The intravascular imaging device of claim 1,wherein the tab is disposed at a distal portion of the flex circuit andthe shelf is positioned at a distal portion of the support member. 6.The intravascular imaging device of claim 1, wherein the support memberdefines a lumen, and wherein the support member includes a recessadjacent to the shelf, the recess defining throughway between the lumenand the tab through which the conductor extends.
 7. An intravascularimaging device comprising: a flexible elongate member sized and shapedfor insertion into a vessel of a patient, the flexible elongate membercomprising a proximal portion and a distal portion; a conductorextending between the proximal and distal portions of the flexibleelongate member; an imaging assembly disposed at the distal portion ofthe flexible elongate member, the imaging assembly including: a flexcircuit coupled to the conductor; and a support member around which theflex circuit is disposed, the support member including: a lumen; and arecess defining throughway to the lumen through which the conductorextends.
 8. The intravascular imaging device of claim 7, wherein therecess is disposed at proximal portion of the support member.
 9. Theintravascular imaging device of claim 7, wherein the recess is shapedand shaped to accommodate the conductor such that an outer diameter ofthe imaging assembly does not increase in an area comprising theconductor and the recess.
 10. The intravascular imaging device of claim7, wherein the recess extends radially inward from an outer surface ofthe support member and through an inner surface of support member to thelumen.
 11. The intravascular imaging device of claim 7, wherein: theflex circuit includes a body and a tab extending therefrom, theconductor being coupled to the flex circuit at a conductive portion ofthe tab; the support member includes shelf on which tab is positioned;and the recess is positioned adjacent to the shelf.
 12. An intravascularimaging device comprising: a flexible elongate member sized and shapedfor insertion into a vessel of a patient, the flexible elongate membercomprising a proximal portion and a distal portion; an imaging assemblydisposed at the distal portion of the flexible elongate member, theimaging assembly including: a flex circuit; and a support member aroundwhich the flex circuit is disposed, the support member comprising aflange at a distal portion thereof; a distal member extending from thesupport member and disposed around the flange, wherein the flange issized and shaped to increase a surface area of the flange to facilitatecoupling between the distal member and the support member.
 13. Theintravascular imaging device of claim 12, further comprising an adhesivedisposed between the distal member and the support member, wherein theflange is sized and shaped to increase a coverage area of the adhesivebetween the distal member and the support member.
 14. The intravascularimaging device of claim 12, wherein the flange is tapered.
 15. Theintravascular imaging device of claim 12, wherein the flange comprises ascrew-thread pattern.
 16. The intravascular imaging device of claim 15,wherein the screw thread pattern comprises a buttress thread pattern.17. The intravascular imaging device of claim 15, wherein the flange issized and shaped to facilitate a locking engagement between the distalmember and the support member.
 18. An intravascular imaging devicecomprising: a flexible elongate member sized and shaped for insertioninto a vessel of a patient, the flexible elongate member comprising aproximal portion and a distal portion; an imaging assembly disposed atthe distal portion of the flexible elongate member, the imaging assemblyincluding: a flex circuit; and a support member around which the flexcircuit is disposed; wherein a portion of the flex circuit is wrapped ina spiral configuration around the support member.
 19. The intravascularimaging device of claim 18, wherein the flex circuit includes a firstsection comprising a plurality of transducers, a second sectioncomprising a plurality of controllers, and a third section comprising aplurality of conductive traces facilitating communication between theplurality of the transducers and the plurality of controllers.
 20. Theintravascular imaging device of claim 18, wherein the third section iswrapped in a spiral configuration around the support member.
 21. Theintravascular imaging device of claim 18, wherein a value of a dimensionof the flex circuit in the third section is less a value of thedimension of the flex circuit in the first and second sections.
 22. Theintravascular imaging device of claim 18, further comprising a coatingdisposed over flex circuit, the coating configured to extend betweengaps in the portion of the flex circuit is wrapped in a spiralconfiguration around the support member. 23.-25. (canceled)